Finding Blocking Code in Async Rust Without Changing a Single Line

📰 Dev.to · Wes

Detect async blocking code in Rust without modifying code, to improve performance and reduce latency

intermediate Published 18 Mar 2026
Action Steps
  1. Use async profiling tools to identify latency spikes and throughput issues
  2. Run the Tokio runtime with the --debug flag to enable debug logging
  3. Configure the async runtime to log blocking calls using the tokio::runtime::Builder::build_with_features method
  4. Test the application under load to reproduce the performance issues
  5. Analyze the logs to find blocking code and optimize it for better performance
Who Needs to Know This

Developers and DevOps teams working with async Rust applications can benefit from this technique to identify and fix performance issues

Key Insight

💡 Async blocking code can cause significant performance issues, and using the right tools and techniques can help identify and fix these issues without modifying the code

Share This
🚀 Detect async blocking code in #Rust without changing a line of code! 🚀

Full Article

You know the symptoms. Latency spikes under load. Throughput that should be higher. A Tokio runtime...
Read full article → ← Back to Reads